Senior Software Engineer – Go (Golang)

Concept Solutions, LLC (CS) is seeking an experienced Senior Software Engineer – Go (Golang) to support a mission-critical application modernization program for a Department of War (DoW) customer.
This program is focused on simplifying access across a portfolio of production applications through a unified sign-on experience, a shared user interface, and a repeatable approach to integrating applications into a common platform.
In this role, you will help maintain and enhance high-volume, public-facing applications while supporting their integration into a modernized platform. The ideal candidate brings strong backend engineering expertise, hands-on production experience with Go, and the ability to troubleshoot, maintain, and securely deploy applications in a cloud environment.

Application Sustainment & Engineering

• Maintain and support a high-volume, public-facing application built with Go, React/TypeScript, and PostgreSQL, containerized on Amazon ECS.
• Hold privileged access to production environments and take ownership of application defects, security patches, and releases in accordance with the customer's release calendar.
• Troubleshoot production issues and implement application fixes to ensure reliability, performance, and availability.
• Maintain application runbooks, operational documentation, and the established sustainment baseline.
• Participate in the Severity 1 on-call rotation and address security vulnerabilities and findings.

Application Modernization & Integration

• Develop and implement application-side changes necessary to integrate existing applications with the shared modernization platform.
• Support identity-provider trust integration, deep-link routing, redemption endpoints, and data feed access.
• Collaborate with engineering and platform teams to maintain existing application functionality during modernization.
• Follow established change management and privileged-access procedures when deploying updates to production environments.

• 7+ years of professional backend software engineering experience, including at least 3 years of production Go (Golang) development.
• Strong experience developing and maintaining REST APIs.
• Hands-on experience with SQL and PostgreSQL databases.
• Experience operating and supporting production applications in a cloud environment.
• Familiarity with formal change control processes and privileged-access security requirements.
• Ability to troubleshoot complex production issues, implement fixes, and support application releases.

Preferred Qualifications

• Experience with React and TypeScript.
• Experience with Amazon ECS or Kubernetes.
• Familiarity with AWS GovCloud environments.
• Experience integrating applications with identity providers using OIDC or SAML.
• Current favorably adjudicated Tier 5 investigation or active Top Secret clearance, enabling immediate privileged access.

Work Location and Schedule

• Location: Hybrid. Work may be performed at Concept Solutions' Reston, VA headquarters and approved remote locations within the United States, with on-site work at government facilities in Northern Virginia and Maryland as required.
• Government-furnished equipment will be used for all access to government environments.
• Schedule: Full-time, 40 hours per week, Monday through Friday, with core hours of 9:00 a.m.–3:00 p.m. Eastern. Work follows two-week Agile sprints, including customer demonstrations each sprint.
• Travel: 0–10%, within the Washington, DC metropolitan area.
• Security Requirement: U.S. citizenship is required. This is a privileged-access position. Candidates must hold a current favorably adjudicated Tier 5 investigation or Top Secret clearance, or be eligible to obtain one. An active clearance may allow for an earlier start.
• Compensation: $170,000–$180,000 annually, depending on experience.

Contract Status: This position is contingent upon contract award, with an anticipated start in October 2026.

Company Profile:

Founded in 1999 and headquartered in Reston, Virginia, Concept Solutions, LLC (CS) is a leading small business in technology, engineering, and management consulting. We are the innovative and agile force behind strategic solutions that enhance organizational efficiency and safeguard our nation across Aerospace, Defense, and National Security sectors.

For over 25 years, CS has been a trusted partner for the Federal Aviation Administration (FAA), Department of Homeland Security (DHS), Department of Justice (DOJ), Department of Defense (DoD) and other federal agencies delivering vital IT, security, and project management services.

Our commitment to excellence is reflected in our adherence to CMMI-DEV ML3, ISO 9001:2015, ISO/IEC 20000-1:2018, and ISO/IEC 27001-1:2013 standards. CS boasts company highlights that include:

• Over two decades of experience across over $300 million in contract awards supporting critical FAA programs
• Multiple contract vehicles providing opportunities across FAA, DoD, NOAA, and other Federal agencies
• Innovation Council - CS maintains an active Internal Research and Development (IR&D) program that is geared towards identifying emerging technologies and pursuing technological innovations

At CS, we know our success stems from our talented team. That’s why we prioritize the wellbeing and growth of our employees, fostering a positive culture centered on innovation, engagement, and career development.

Benefits: Concept Solutions offers a competitive benefits and salary package you would receive from a large company. We offer health, dental, vision and life insurance, as well as a comprehensive 401(k) plan with matching and immediate vesting.

Concept Solutions is an Equal Opportunity Employer, and we value workplace diversity. We invite resumes from all interested parties and consider applicants for all positions without regard to race, color, religion, sex, national origin, age, marital status, sexual preference, personal appearance, family responsibility, the presence of a non-job-related medical condition or physical disability, matriculation, political affiliation, veteran status, or any other legally protected status. Concept Solutions is a VEVRAA federal contractor, and we request priority referral of veterans for available positions.